Description

CREATE ROLE adds a new role to a Greenplum Database system. A role
is an entity that can own database objects and have database privileges. A role can
be considered a user, a group, or both depending on how it is used. You must have
CREATEROLE privilege or be a database superuser to use this
command.

Note that roles are defined at the system-level and are valid for all databases in
your Greenplum Database system.

Parameters

name

The name of the new role.

SUPERUSER

NOSUPERUSER

If SUPERUSER is specified, the role being defined will be a
superuser, who can override all access restrictions within the database.
Superuser status is dangerous and should be used only when really needed.
You must yourself be a superuser to create a new superuser.
NOSUPERUSER is the default.

CREATEDB

NOCREATEDB

If CREATEDB is specified, the role being defined will be
allowed to create new databases. NOCREATEDB (the default)
will deny a role the ability to create databases.

CREATEROLE

NOCREATEROLE

If CREATEDB is specified, the role being defined will be
allowed to create new roles, alter other roles, and drop other roles.
NOCREATEROLE (the default) will deny a role the ability
to create roles or modify roles other than their own.

CREATEUSER

NOCREATEUSER

These clauses are obsolete, but still accepted, spellings of
SUPERUSER and NOSUPERUSER. Note that
they are not equivalent to the CREATEROLE and
NOCREATEROLE clauses.

CREATEEXTTABLE

NOCREATEEXTTABLE

If CREATEEXTTABLE is specified, the role being defined is
allowed to create external tables. The default type is
readable and the default protocol is
gpfdist if not specified.
NOCREATEEXTTABLE (the default) denies the role the
ability to create external tables. Note that external tables that use the
file or execute protocols can only be
created by superusers.

INHERIT

NOINHERIT

If specified, INHERIT (the default) allows the role to use
whatever database privileges have been granted to all roles it is directly
or indirectly a member of. With NOINHERIT, membership in
another role only grants the ability to SET ROLE to that
other role.

LOGIN

NOLOGIN

If specified, LOGIN allows a role to log in to a database.
A role having the LOGIN attribute can be thought of as a
user. Roles with NOLOGIN (the default) are useful for
managing database privileges, and can be thought of as groups.

CONNECTION LIMIT connlimit

The number maximum of concurrent connections this role can make. The default
of -1 means there is no limitation.

PASSWORD password

Sets the user password for roles with the LOGIN attribute.
If you do not plan to use password authentication you can omit this option.
If no password is specified, the password will be set to null and password
authentication will always fail for that user. A null password can
optionally be written explicitly as PASSWORD NULL.

ENCRYPTED

UNENCRYPTED

These key words control whether the password is stored encrypted in the
system catalogs. (If neither is specified, the default behavior is
determined by the configuration parameter
password_encryption.) If the presented password
string is already in MD5-encrypted format, then it is stored encrypted
as-is, regardless of whether ENCRYPTED or
UNENCRYPTED is specified (since the system cannot
decrypt the specified encrypted password string). This allows reloading of
encrypted passwords during dump/restore.

Note that older clients may lack support for the MD5 authentication
mechanism that is needed to work with passwords that are stored encrypted.

VALID UNTIL 'timestamp'

The VALID UNTIL clause sets a date and time after which the role's password
is no longer valid. If this clause is omitted the password will never
expire.

IN ROLE rolename

Adds the new role as a member of the named roles. Note that there is no
option to add the new role as an administrator; use a separate
GRANT command to do that.

ROLE rolename

Adds the named roles as members of this role, making this new role a
group.

ADMIN rolename

The ADMIN clause is like ROLE, but the
named roles are added to the new role WITH ADMIN OPTION,
giving them the right to grant membership in this role to others.

RESOURCE GROUP group_name

The name of the resource group to assign to the the new role. The role will
be subject to the concurrent transaction, memory, and CPU limits configured
for the resource group. You can assign a single resource group to one or
more roles.

If you do not specify a resource group for a new role, the role is
automatically assigned the default resource group for the role's capability,
admin_group for SUPERUSER roles,
default_group for non-admin roles.

You can assign the admin_group resource group to any role
having the SUPERUSER attribute.

You can assign the default_group resource group to any
role.

You cannot assign a resource group that you create for an external component to a role.

RESOURCE QUEUE queue_name

The name of the resource queue to which the new user-level role is to be
assigned. Only roles with LOGIN privilege can be assigned
to a resource queue. The special keyword NONE means that
the role is assigned to the default resource queue. A role can only belong
to one resource queue.

Roles with the SUPERUSER attribute are exempt from resource
queue limits. For a superuser role, queries always run immediately
regardless of limits imposed by an assigned resource queue.

DENY deny_point

DENY BETWEEN deny_point AND
deny_point

The DENY and DENY BETWEEN keywords set
time-based constraints that are enforced at login. DENY
sets a day or a day and time to deny access. DENY BETWEEN
sets an interval during which access is denied. Both use the parameter
deny_point that has the following format:

For more information and examples about time-based constraints, see
"Managing Roles and Privileges" in the Greenplum Database Administrator
Guide.

Notes

The preferred way to add and remove role members (manage groups) is to use
GRANT and REVOKE.

The VALID UNTIL clause defines an expiration time for a password
only, not for the role. The expiration time is not enforced when logging in using a
non-password-based authentication method.

The INHERIT attribute governs inheritance of grantable privileges
(access privileges for database objects and role memberships). It does not apply to
the special role attributes set by CREATE ROLE and ALTER
ROLE. For example, being a member of a role with
CREATEDB privilege does not immediately grant the ability to
create databases, even if INHERIT is set. These
privileges/attributes are never inherited: SUPERUSER,
CREATEDB, CREATEROLE,
CREATEEXTTABLE, LOGIN, RESOURCE
GROUP, and RESOURCE QUEUE. The attributes must be set
on each user-level role.

The INHERIT attribute is the default for reasons of backwards
compatibility. In prior releases of Greenplum Database, users always had access to
all privileges of groups they were members of. However, NOINHERIT
provides a closer match to the semantics specified in the SQL standard.

Be careful with the CREATEROLE privilege. There is no concept of
inheritance for the privileges of a CREATEROLE-role. That means
that even if a role does not have a certain privilege but is allowed to create other
roles, it can easily create another role with different privileges than its own
(except for creating roles with superuser privileges). For example, if a role has
the CREATEROLE privilege but not the CREATEDB
privilege, it can create a new role with the CREATEDB privilege.
Therefore, regard roles that have the CREATEROLE privilege as
almost-superuser-roles.

The CONNECTION LIMIT option is never enforced for superusers.

Caution must be exercised when specifying an unencrypted password with this command.
The password will be transmitted to the server in clear-text, and it might also be
logged in the client's command history or the server log. The client program
createuser, however, transmits the password encrypted. Also,
psql contains a command \password that can be used to safely change
the password later.

Examples

Create a role that can log in, but don't give it a password:

CREATE ROLE jonathan LOGIN;

Create a role that belongs to a resource queue:

CREATE ROLE jonathan LOGIN RESOURCE QUEUE poweruser;

Create a role with a password that is valid until the end of 2016 (CREATE
USER is the same as CREATE ROLE except that it implies
LOGIN):

CREATE USER joelle WITH PASSWORD 'jw8s0F4' VALID UNTIL '2017-01-01';

Create a role that can create databases and manage other roles:

CREATE ROLE admin WITH CREATEDB CREATEROLE;

Create a role that does not allow login access on Sundays:

CREATE ROLE user3 DENY DAY 'Sunday';

Create a role, assigning a resource group:

CREATE ROLE bill RESOURCE GROUP rg_light;

Compatibility

The SQL standard defines the concepts of users and roles, but it regards them as
distinct concepts and leaves all commands defining users to be specified by the
database implementation. In Greenplum Database users and roles are unified into a
single type of object. Roles therefore have many more optional attributes than they
do in the standard.

CREATE ROLE is in the SQL standard, but the standard only requires
the syntax:

CREATE ROLE name [WITH ADMIN rolename]

Allowing multiple initial administrators, and all the other options of CREATE
ROLE, are Greenplum Database extensions.

The behavior specified by the SQL standard is most closely approximated by giving
users the NOINHERIT attribute, while roles are given the
INHERIT attribute.